More explanation.

Author: Simon MacMullen

scripts/rabbitmq-env

@@ -15,13 +15,14 @@
 ##  Copyright (c) 2007-2014 GoPivotal, Inc.  All rights reserved.
 ##
 
-## readlink exits with an error if the given argument is
-## not a symlink
+# We set +e here since since our test for "readlink -f" below needs to
+# be able to fail.
 set +e
 # Determine where this script is really located (if this script is
 # invoked from another script, this is the location of the caller)
 SCRIPT_PATH="$0"
 while [ -h "$SCRIPT_PATH" ] ; do
+    # Determine if readlink -f is supported at all. TODO clean this up.
     FULL_PATH=`readlink -f $SCRIPT_PATH 2>/dev/null`
     if [ "$?" != "0" ]; then
       REL_PATH=`readlink $SCRIPT_PATH`